I would like to turn a file into a (lazy) sequence...

# announcements

[poohbar]

I would like to turn a file into a (lazy) sequence of lines, so I did this:

File(path).bufferedReader().lineSequence()

Now, lineSequence() warns that I have to take care of closing the input stream but how would I go about doing that? E.g. how do I know the sequence has been exhausted and it's time to close the flie?
I can't use useLines() in this case, because I am returning this sequence out of a function.